Southwest Missouri farmers are asking questions about the late planting of winter wheat since conditions were not ideal during regular planting time.
"It is risky to plant wheat so late in the season due to lack of weather conditions that support vernalization," said Jill Scheidt, field specialist in agronomy with University of Missouri Extension. "Fall tillering contributes the most to wheat yield; spring tillering is secondary and unlikely to produce enough tillers to make a good yield."
Winter wheat requires vernalization which is a process where plants exposed to cold temperatures experience physiological changes. With wheat, this means the plants will not flower until vernalization occurs.
The degree of vernalization required can vary within a species and variety. The best vernalization temperatures for winter wheat are between 40 and 50 degrees Fahrenheit, not colder temperatures.
According to Nebraska Extension, 45 days of vernalization is optimum for yield production.
Kansas State University researchers conducted a seven-year study, seeding winter wheat every month from Oct. 1 to April 1.
Grain yields declined the longer planting was delayed after Oct. 1 (the optimum planting date for that area). In southwest Missouri, the optimum planting date is Oct. 10.
"With the later planting dates, the grain-filling period was progressively shortened and delayed into warmer weather. General declines occurred in mature plant height, number of heads per plant, number of kernels per plant, and grain test weight," Scheidt said.
In the Kansas study, wheat planted after Dec. 1, was at 59 percent of potential yield and wheat planted after Feb. 1, was at 41 percent of potential yield.
"Spring wheat is not a good option for Missouri as weather conditions are often too hot for wheat to produce well," Scheidt said.
For more information about the MU Extension field crop scouting report program or for information specific to planting winter wheat, contact Jill Scheidt at the Barton County Extension office at 417-682-3579.